Engine-starting apparatus



May 19, 192s.

, J. BIJUR ENGINE STARTING APPARATUS Original Filed Oct.

2, 1919 2 Sheets-Sheet 1 ,27 /ZV H UNIL-wf, w L ff] L iVENTOR Joseph Buur, BY/@fwfma ATTORNEY ENGINE STARTING APPARATUS Original Filed Oct. 2, 1919 2 Sheets-Sheet 2 33 /9 @QM- UNM lil INVENTOR ATTORNEY Patented May 19, 1925.

UNITED STATES P 1,537,932 ATENT OFFICE.

JOSEPH nIJUa, or NEW Yonx, N. Y., AssIGNoR, BY MEsNE ASSIGNMENTS, To. ECLIPSE MACHINE COMPANY, or ELMIRA HEIGHTS, NEW YORK, A CORPORATION or NEW Your.

`Application led October` 2, 1919, Serial No. 327,920. Renewed October 2, 1924.

, Tol tuihmn t may concern.' i Be .it known that I, JOSEPH BIJUR, a citizen "ofithefUnited States, residing at New AYork,` city, in the county of New Yorkl and.

yStateofvNew York, have invented certain newf'andz useful Improvements in EnginevStarting Apparatus, of which the following .is-a clearvandexact description, such as will enablej others skilledv in the art to which it appertains'to make anduse the same.

' Thisjivnvention relates to engine starting apparatus more especially to such as are emi ployed for starting automotive engines, and y theflinvention has particular application to ,15 aviation engines, y

One of the objects is to provide apparatus "forjstarting a source of power which appa- .ratus'shallv-be of compact and durable conl. struction as well as reliable' inaction. Another Object is to provideapparatus of the, f`typereferred to which shall be easy of l application lto aviation engines, particularly lto suchas are not designedto carry starters and finlwh'ich the available space is inadequate for readyy mounting of types of starters heretofore .used on automobile engines. The invention has especial yutility for starting the United States Liberty engine, though it has av much broader field of appiication. ther'objects will be in part o vious and in part pointed out hereinafter. The invention accordingly consists in the featuresf-fconstruction', combinationsy of elements vand arrangement of parts which inafterfset'forth, and the scope of -'the application Ofwhich will 4be indicated 1n the following claims.

In the accompanying drawings wherein is shown one of various'possible embodiments of the several features of this invention,

Fig. 1 is a view in longitudinal sectionof myy starter as applied to the engine, the pinion i being shown out of mesh, Fig. 2 ris afragmcntaryview showing the pinion in buttin position and the shifting mechanism biasel to relieve the butt, Fig. 3 is a fragmentary [frontview of the starter'unit, Fig. 4 is a detail sectional View taken along line 4 4 vof Fig. 1rv and Fig. 5 is a. fragmentary View Of the pinion and its mount in isometric perspective.` Similar-.reference characters refer to simithe drawings.

will be exemplified in the construction herelar partsthronghout the different views of.

Referring now to the accompanying drawings I have shown a fragment of the nose 1 of an engine, which I define as that part of the crankcase in advance of the cylinder base 2. The proportions shown are illustratively those ofthe Liberty engine. Other details of this engine are not material to this invention and are, therefore, not shown.. At the vforward end of the crankshaft 3 is a hub 4 for the usual propeller or airscrew a fragment of which is shown at 5.v Secured to the propeller hub by means of bolts 6 I provide a ring 7 having spur gear teeth 8 at its periphery through which the torque of the starting motor is applied to the engine. The specific construction of the gear ring 7 and its application and manner of use constitute no part of the invention claimed herein and the description thereof need not, therefore, be given in greater detail. This 7 subject-matter is fully described and claimed in-niy copending application Serial No. 224,- 494 filed March 25th, 1918, now Patent 1,429,670.

In thc following description of my starting apparatus, I will designate the end ad-V jacent gear ring 7 as the forward or front end, and the opposite as the rear end.

To apply the torque vat the gear teeth 8 on the ring 7 I provide an electric starting-I motor M connected to Vrotate a coaxial toothed driving member or pinion 9 the teeth 10 of which are preferably chamfered as at 11.'V The` pinion is normally displaced from the gear 7 but adapted preferably through the agency of automatic shifting mechanism to be brought into mesh there--` 'with By reason of the restricted length of the nose of an engine of the type referred to, which in the relatively large Liberty engine, for instance, is but seven inches, the shifting mechanism has a telescoped relation to the length of the motor so that the overall length of motor and shifting mechanism is sufticientlysmall to render possible the disposition of the starting unit, comprising the motor, shifting mechanism and pinion in the limited space available.

The ,starting unit is preferably held in proper alignment with the lgear ring 7 by 105 lodging the Fcylindrical surface of its yoke 12 in a corresponding seat in a cradle 13. The rear of cradle 13 has a pair of lugs 14 fitting upon corresponding bosses 15 formed as regular parts of the construtn of the engine, a pair of bolts 16 constituting a part of the engine construction passing each through one said boss and the corresponding lug and having nuts 17 threaded and locked one to the end of each to firmly secure the lugs 14 upon the engine. Similar lugs 18 are provided at the other end of the cradle resting upon a channel shaped platform 19, a pair of bosses 20 on the engine forming a support for said platform and bolts 21 securing said platform to the engine. The height of the platform is such as to bring its supporting surface 22 on a level with the botom of lugs 14 so that lugs 18` may rest upon said surface 22 and may be secured thereto by bolts as at 23.

The yoke 12 of the motor is preferably provided with two pairs of radial studs 24 adapted to register with corresponding notches 25 cut into the opposite edges of the cradle 13, lock nuts 26 serving to secure said studs with respect to the'cradle. It is seen that the motor can'thus be readily applied to the engine, the radial studs passing along land into the slots as the motor is laid upon its cradle and being readily removable therefrom after the nuts 26 are removed.

Within the yoke 12 ofthe motor is secured a stator or field construction 27 within which is mounted a rotor in the form of an armature 28 disposed between end heads 29 and 30 telescoped over the yoke, and held together preferably by bolts 31. The varmature is preferably provided with a relatively lar e axialopening 32, the laminations 33 of its core 34 fitting over a hollow shell 35 and bein held against rotation thereon by means o a key 36 preferably weldedv into a. depression 36 in the shell and fitting into a registering notch 37 in each of the laminations, said notches constituting a key way in the core. The laminations of the core are firmly heldagainst separation between a shoulder 38 on the shell in contact with an insulation piece 39 at one end of the armature core and a lock ring 40 fitting into a groove in shell 35 and pressing against a washer 41 at the other end of the core. The armature windings 42 fit into slots in the core, in the well-understood manner and'are connected to the usual commutator 43 built upon the end-pf' the shell 35'.

For mounting the 'armature in proper assembled relation between the heads 29 and 30 I provide the heads respeotivelywith central bearings 44 and 45 extending respectively into 'inwardly extending hubs 46 and 47. About hub46 I dispose a ball bearing 48 for supporting one end of the armature shell 35. A slidable shaft 49 extends through bearing 44 and supports one end of the shell 3.5 which latter has an inwardly extending flange 50 that surrounds a bushing 51 about the rear end of the shaft. The

bushing 51 extends into bearing 45 and is held against longitudinal movement by an integral flange 52 abutting shell flange 5() and a washer 53 fitting into a groove 54 in the bushing and between flange 50 and the bearing 45. It is Seen that the pinion carrying shaft 49 completely closes the opening to the shell at each end of the armature, thus preventing entry of dust or dirt into the vmechanical shifting mechanism enclosed thereby.

The pinion 9 is preferably mounted upon the forward end of the shaft by means of a bolt 55 passing axially 4through the pinion and into the forward end of the shaft and threaded at its innerI end as at 56. A taper pin 57 .is seated in a depression in the shaft as at 58 and fits Vin the bifurcated end 59 of the bolt 55 so that when said bolt is screwed home to secure the pinion 9 against the end of the shaft, the taper pin will expand the threads to firmly tighten the pinion upon the en d of the shaft. Cooperating radial splines 84 effect a positive drive between'the shaft and the pinion. The pinion is thus disposed on the outsideof end head 29. The head is preferably formed with a concavity as shown in which the pinion is lodged, thus avoiding a lengthening of the starting unit construction. i

The transmission mechanism for shifting the pinion 9 to bring it into mesh with the teeth of the gear riiig 7 andfor then transmitting the cranking torque is preferably of Ithe automatic type. The preferred conlll() struction shown on the drawings includes a clutch unit designated in its entirety by numeral 60 said unit comprising a nut 6l cooperating with threads 62 cut in the inner surface of shell 35; a clutch plate 63 having splines 64 intertting corresponding splines 65'on shaft 49 and a clutch' washer 66 of cork or the' like interposed between said plate and the flange 67 on said nut, and secured to said plate by any appropriate means (not shown). The plate 63 may be provided with an extension 63 Cooperating with splines 65. The extension 63 gives length to the bearingof plate 63 on the shaft 49 and splines 65 and thus prevents the clutch unit from tilting with reference .to the shaft and thereby being cramped thereon.- This extension 63v also supports the end of spring-69 clear of the shaft 49. Interposed between the clutch plate 63 and a flange 68 formed integrally with the shaft 49 'I provide a relatively strong coil spring 69 which encircles the shaft 49 and urges the clutch unit against a stop lnut 70 threaded upon the rear end of shaft 49. A dished spring washer is preferably interposed between flange 68 and spring 69, said washer being of a stiffness less than that of the said spring. The spring 69 as is apparent, imparts an initial torque to the friction clutch CII maiz/,ess

unit 60. The torque on the clutch is variable depending on the compression of spring 69ans Will appear more fully below. c

Upon the side of the mit 'Harige 67 opposie tlit of clutch Washer 66,1 form :i oonstzmt torque clutch the purpose of which will appear more -ully below. This slut/cli comprises a clutch plate 7l lsplined to-shst Si es at 72 and contacting the nut flange, and e (lished spring Washer '73 fitting `ogmiiisnc elle plate 71 and held inplace under e xed con'ipi'ession by s lock ring 7 4 iting in s groove 75 in. ille not 61. An annulsi washer 76 is preferably interposedbetwecn the (lished spring andthe look rino.

The transmission is preferably poviefl wiiili s buffer mounteil inside the sheli 35 and; comprising a mit 77 tluesclecl into the ll, zin impact washes 78 and s plurality of disiiecl spring steel n'sslie's 79 inieposed between the nut 77 enel the impact washer 78 ond urging Seial impact Washer iigsins' stops 80' preferably ioiminp; the encieof ilie sciewliieeds 62,

To pieveiit cieeping movement el' olie pinion ogetliei with shaft i9 While joe sarer is noil in sse9 a conical coil spiking 8i, is pseifeiably pi'oviecl, abutsingr ehe flange o8 on the slis'lii ils smalle? enel snai iittiog 'mio o, ieeinei? 83 ennuis? in forni at its Ween 'the bail ees?. si?, 48 intl the sinon-klei: 85:5 on 'lalie shell. Spring; 8l iesisis fille oui- Werei Soievel o the slie'is e9 which, Wiili die 1 ico. 9, sliereioie enfxs 'o sessie with the au' 'ieiii'e pii'ioi orinesiiing the stifness oi lie spring is *cisoly such *Limia the pinion iooeies shi d i en ongle of sppi'oxi mseljf ninetyileglees slewing iis advance toweid mesh, siieiebjf reducing lie 4clisnce ci boiling oz sessie A lViy starting; moo? ,may be esseiiiblecl es follows: The spying @59- is iisl; slipped over the iesi" end ci olie smite@ 'whereupon Jolie cimeli essembly rfisolenp of clutch pisse 6?, cl l ifsslieo eoclzijet ol enel the conste/11@ y oe cl1itcb eiemeif si, 73a 74 escl 76 is pessecl ove-i the one ilie shalt into scopes ation with the' iiies 55 es seid shells. @beroepen folie sieL not 70 is ililleeiieii loclecl onto the cnil ci iHoe The spring 8l seing firstpsssel owes lie lei'warcl eiiii'o che slieizi, sbis'sli. inserteii yinto ille sliell 35 ol? the armer, o f, .lie not emeringiiiito "iliiesciecl coopeie, i "with the, tlircscls o?. in ssiel shell, tliecuieif cossi'iiclioo 77, 78, 79 lisvmg bee-opievioiisly plaeesl into che slieil. The bushing l is 'chen opolie new ehe resi: elle slief enclilfie'ifil in piece i337 the Washes "n The bell beeiing S kbeing 'mounte wiiliiii lie heed 29, 'the two end heads may lie plsced in position and secured with/fre to the yoke bolts The'piio ion 9 may then be epplied, *she boit 55 bein-.g iiiiiesiled in position end .being 'looked iviieife 4boiein As the pinion 9 is new in in by the Wedging action of' the taper pin 57 in the manner obvious from the description vof the constiuction above.

In operation, the motor being assumed mounted; in position, s stating switch (not shown) 'preferably of the non-resistance type is closed bo connect the motor with s source of surfent piefembly :i ystorage beiu rteiy (not shown). The armature starts mpid rotation together with the tiueodecl shell which is an integral pari'. theieof. The icuii (il being i'otetoble :is a unit with the clutch elements, 9, he ineiie of ibis assembly of' posts will prevent. tbe mit from immediately taking up tbe rotation of the shaft. Consequently the mit; will sdvsnce pushing simil; 49 and pinion 9 oiworly through the compression spring 69 against the i'esistencc of spring 81, misil the pinion is in mesh Witl'i seeth 8 on the gees ring 7. The acsion of spring 8l assures s slew rotation of die pinion ss above poiiicecl out y'i'.lius facilitating; *che meshing eolien. lflillien *die pinion is in mesh, lumber sclvciice oi the shaft and pills ion is srongly resisted by engagement of clu'lcii plete G3 with iinpfio; piste 78 of the cranking connection Wih goei? ring 7 snai the engine esiss iozstion of ille leiter., ihe pinion wil tend to coniniie its mlvsnce ogelier wish is shaft, 'sluis gigbiening *elle riciion cluizcli until slice mit is compelleol to sessie es n unit with the sicmetuie emi its shell. Il lie iesisszince o ithe engine "co cizinliiig is sui-iii cientiy iiiffn.q "che disliecl washers 7 9 may be come peifislly or wholly compressed beioie be clutch 60 lies he needed tightness 'ioi ilelivei'ing she cieiiliinp; loiquei @milking ioilque is tinisyielflingiy tsnsmitied from ilieshell 35 hiougli she nul; iii., the ifictioii eluch assembly, the simile All) enel lie pinion 9 to Clie gem' iiiig 7 on. olie engine llillien il'ie engine ssi'e uncles iss own power. e mie of ioteiicn. is impzulel to the pinion@ owl ils sssooieecl slie'l 4:9 gi'esiei: 'folien die wie impsiecl so the shell by ilie motor. llie nos coosequenly oveiiuns shell elias eciiing; lo osiginel posiiioii sod by" 'reason oi iis coiisc; Wiii ille sie@ zool; lie sliec i9 is also Wiiicliswe thus cliswiog one pinion 9 ous of mesh io che posiioo' shown is Fig., i, I

filhile olie aeroplane oi* otlieivehicle e uiopecl Wish is sieste? is runninff the spring Si iesiss' any occidental unclesiiecl advance ci the pinion 9 with slisi. 49 into `com-occ wili the geei'ecl icing 7 engl ibis iegsidless of `like gre-cle or roughness of "elle course.

Mesliing of the pinion Wish she gesiring isili ordinarily ineke plz-ice i'ezilily os bile clismered constiuctioo shown si; li facili- 'lates' ent-ry of 'che pinion eelli, Should however pinion teo-#iii imposes lie shaft lll) omi the pinion lil@ the gear ring directly end to end so that the pinion and with it the shaft 49 are arrested in both their forward and rotary movement, thus preventing entry, then' the nut 61 should advance along both the threads 62 in the shell and the splines 65 on the shaft, thereby compressing the spring 69 to tighten the clutch 60 until the nut commences rotating with the shell. A slight rotationof the shaft will be sutiicient to bring the teeth ot the pinion out of butting into meshing alignment with the gear teeth at which time rapid expansion ot coil spring 69 will urge the pinion into full mesh with the gear ring, whereupon vthe normal cranking and demeshing will proceed as above described.

lf the construction thus :tar described in the operation, alone were employed it might occur, immediately after butting of the teeth that the pressure exerted by the spring 69 does notimpart suiici'ent torque to the clutch G0 to allow it to turn the pinion into meshing alignment, in whichr event the nut would rotate with the shell, therefore failing to advance, the clutch would slip, and the gears remain in butting condition as long as the motor was energized. This is prevented by the constant torque clutch '71-76 the holding power of which is added to that of the variable torque clutch to prevent a rot-aL tion of the nut with the armature even under the most severe conditions of but thus coinpeiling advance of the nut, tightening of clutch GO and reliet1 of but in the manner above described. The constant torque clutch 71-76 thus assists the variable torque clutch to compel advance in butt relief when the latter is at its Weakest. After the variable torque clutch has become tightened to a certain extent in the manner above set forth,

the assistance of the constant torque clutch is no longer needed to cause further advance. ln the construction shown, however, the constant torque clutch transmits a portion of the torque throughout the operation et the starter.

Although i have shown my starter ina preferred a plieation to aviation engines it is to be un erstood that this starter is also applicable 'to engines for propelling other types ot' vehicles such as automobiles and motor boats, and that this invention is :turther applicable to the starting of stationary engines.

it is further to be noted that starting unit may be mounted to cooperate with the end of the crank-shaft oppositethey propeller, or with other parts of the engine and that other mounting means for vthis unit may be employed.

While 1 have shown a construction in which the scievvthreads tir-inclined splines are on the shell and the straight splines on the shaft and although this is my preferred construction, it is :to be understood that beneficial results may be obtained by placing the. screwthreads on the shaft and the straight splines on the shell as will be apparent from my -copendi'ng application Serial No. 224,494 filed. March 25th, 1918.

The construction for shifting and transmitting torque has certain features in coininon with that of my copending application Serial No. 145,839 filed Febiiiary-1st, 1917, such common subject-matter beinefully claimed in the latter application and), therefore, not claimed' herein.

It will thus be seen that there is herein described apparatus in which the several features of this invention are embodied, and which apparatus in its action attains the various objects of the invention and is well suited to meet the requirements of practical use.

As many changes could be made in the above, construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all mattei' contained in the labove description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters-Patent is '1. An engine starter, comprising in combination a motor a iiiion ada ted to be i engaged with an engine, and shitting means for said pinion having a portion extending.

between the ends of the motor, said shifting means comprising an internally threaded shell, a splined, slidable shaft coaxial therewith, and a member cooperating with said threads and with said splines, said pinion beine on the end of said shaft.

2. ihe combination, in an engine starter, of a shell having inclined guide means, a splined, slidable' shaft passing through said shell coaxially therewith, a pinion on said shaft, shifting means for said pinion, comprising a member encircling said shaft and intertitting said' guide means, and means transmitting torque to said pinion.

8. The combination, in an engine starter, of a shell having inclined guide means, a,

spiined, slidable shaft passing through said shell coaxially therewith, a pinion on said shaft, shifting means for said pinion, coinprising a member encircling said shaft and "interiitting said guide means, and means transmitting torque 'to said pinion. said means including' assit-tightening friction clutch.

' 4. The combination, in an engine starter. of aA shell having inclined. guide. means. a splined, slidable shaft a pinion on said Shaft, a control member coacting with said guide means, a clutch plate encircling said shaft interlitting the passing therethrough, p

splines thereof, and a friction clutch washer between said control membergand' Said clutch plate. v

5L The combination, in anjenginel-starter,

' 'o a motor,ashell, and a slidable shaft passing therethrough, a driving inion on one of the latter I nenibers,I a c utchv unit in threaded relation to saidshell and ins lined l ,relation to said shaft, for causing ta vance of the pinion carrying member kto meshing position 'responsive to starting of the niotor, said clutch thenfunctioning to transmit the cranking torque.

6, The combination, inl an engine starter, of a shell kinternally threaded, a splined, slidable shaft passing therethrough, a pin- .Y ion mounted near theforward end of said "shaft, a clutch unit in threaded relation to vsald shell and* in' vsplined relation to said shaft lwhereby said, clutch yunit `may move forwardly with respect 'tosaid shell, and meansv for transmitting the forward movenient of said clutch to said shaft and for then f ytransinitting,the torque through said clutch.

7..,f1'1`he`combination, infan engine starter,

of u a.v shell,`- a" Slida-ble shaft. passing v therethrough and having a pinion nionted near fitsforwardl end, a friction clutch unit in endl thr ided relation to said shell and lin splined of motor, a rotatable shell., a slidaole shaft passing* 'therethrough coaxially' therea'fith, aving a toothed driving member near its iorvverd end and shifting means connected hetWeenr said shell and vsaid shaft, and

i 'lading' starringY for .pushing said shaft orvfardljvfor nieshinglof said pinion, responsive to. starting of the motor.

- r The oornloination, in engine starter, ott s, motor, rotatable shell, a slidable shaft psssing theretlirongli coairially therewith anl having a driving pinion neer itstor'- ward end, and shiftingmeans including a' not interposuedbetween said shell and said shaft and threaded to one thereof9 and a coil springy in the path 'of said not, and having a part oit the sha-tt in'its path, whereby upon starting ol."k the motor the shaft will be spring pressed ortvardly for mesh of vsaid pinion.

1Q. The 'coinhinatiomin an engine starter,

of motor, afrotatable shell, slidahle shaft 5 n f n n l saving 4driving pinion neer its tornterieoediate its f end a shoulder ends, pinion shitting. re As incnding i snit ir seed elett-Ween said l a I il. The combination, in an engine starter, of a motor, a rotatable shell, a slidable shaft passing therethrough coaxially thereof, said shell 'having a driving inion near its forward end and a shoiil er intermediate its ends, a friction clutch unit interposed between 'said shell and said shaft, and coinprising a nut threaded into said shell, a

vclutch plate slined to said shaft-and a Washer of cor or the like interposed between o'ne face of said lint and said plate,

and a coil spring encircling said shaft and interposed between said plate and said shoulder.

12. The combination, in an engine starter, of a motor, a rotatable shell, a slidable shaft passing therethrough coaxially thereof, said shaft having a driving pinion near its for- WardY end and a shoulder intermediate 'its ends, a friction clutch unit interposed betiveen said shell and said shaft, and cornprising a nut threaded into said shell, a

clutch plate splined to said Shaft and a,

4clutch Washer interposed loetvveen one-face of said nut and said plate, a coil spring encircling said shaft and interposed between said plate 'and said shoulder, snol a'plurality ot annular dished Washers in said shell and adapted to yieldingly arrest `said plate when cranking torque is shout t he delivers-id.`

i3, rll'ie combination, inL en engine starter, o?? motor, a shell, shaft passing therethrough and coarlialljv thereo, a pinion mounted on one oif said latter elements, and a. friction clntthv unit interposed between said shell and said shaft and eoinprisinga not threaded to said shell, a clutch folatev splined to said shaft, a clutch 'washer inter- "peset .ietvveen one `ace oit said nut and said plate, constant torque clutch cooperating withL the other Jtace o' said not., and a spring tor causing tightening tit-said tirst clutch as said'spring; is distorted,

lil The combination, in engine starter,

ot a motor, a rotatable shell, a slidable shaft passing' therethrough eoaxiaily thereof, said shell having a driving: pinion near .its for- Ward end and a shoulder intermediate .its ends, a friction clutch' unit interposed betva-een said shell and said shaft, and conprising a not threaded into said shell, a cliiteh plate splined to said shaft and aelotch WasherA interposed between one face et not and said plate, e coil spring encircling* said shaft end interposed between plate and seid shonldenend a constant le clutch including a plate lto and pressing ageinst the other oi@ said not, spring' against plate, loch encireling .the

peripherv o nid not and lio, no plete, i? niais inge t l ng pressions lett-veen iio X of ashell, the rotor of a motor encircling said vshell and secured thereto, a slidable shaft passing through said shell coaxially therewith and bearing a toothedy drivin member, and shifting mechanism for sai shaft'threaded to said shell and splined to 'said' shaft.

16.- The combination, in an engine starter, of an armature having an internal cylindrical threaded Wall, a splined shaft coaxial of said Wall and'carrying a pinion, a clutch unit interitting. the threads of said wall and the splines of saidshaft, and a spring interposed between said unit' and said shaft, whereby upon starting of the motor, the shaft will be yieldingly shifted to move said pinion into meshing position, and thereupon said clutch will betightened to -transmit cranking torque.,l l

17. The combination, in an engine starter,

of a motor, having an annular armature, end heads for said motor, a driving pinion on the exposed side of one said end head, shifting mechanism for said driving pinion a extending through the axial opening in said armature and constituting, an armature support, bearings in'said end heads for saidarmature and shifting construction, said shifting construction comprising .splines rigid with said pinion, splines'rotatabl'e with pinion Will tending through the axial opening in said armature and vconstituting an armature support, bearings in said end heads for said armature and shifting construction, said shifting construction lcomprising splines rigid with said pinionand screw threads rigid with said armature, and a clutch unit having a nut co-operatinglwith said screw threads, a clutch plate interfitting said splines, and a friction Washer interposed between said nut and said plate; and a spring interposed between said plate and a part rigid with said pinion to push said inion into mesh by the advance of said clutc I.unit when the motor is started.

In testimony whereof, I have signed my lname to this specification this 24th d ay of September, 1919.

JOSEPH Burn 

